From ‘Superman’ to ‘The Hangover,’ many 2013 movie releases will be follow-ups to past hits.

The third movie featuring Robert Downey Jr. as the sarcastic, metal-clad do-gooder opened to an estimated $175.3 million from screenings in Canada and the U.S. that started Thursday night and ran through Sunday.

That was behind only Marvel’s “Avengers,” which opened with $207.4 million last May. “Avengers” featured Iron Man as well as other Marvel comic heroes.

“Iron Man 3″ sold an estimated $175.9 million in tickets abroad over the weekend. It opened in most countries a week before it did in the U.S. and has brought in a total of $505 million overseas.

Attendees sitting in front of a poster during a promotional event for the Hollywood movie ”Iron Man 3” at the Forbidden City in Beijing.

Watch Iron Man 3 Online or Download Iron Man 3 Movie : The movie’s performance in China was particularly strong. Since opening there Wednesday, “Iron Man 3” has collected $63.5 million in the country, easing worries that Chinese moviegoers were becoming more interested in domestic productions than in Hollywood imports.

“Iron Man 3” also proved strong in South Korea, the U.K., Mexico and Brazil. The movie was running ahead of “Avengers” in several countries, including Russia, South Korea and China, if early estimates there prove accurate.

Watch Iron Man 3 Online or Download Iron Man 3 Movie : While “Iron Man 3” is unlikely to match the world-wide total of $1.5 billion for “Avengers,” the new movie is on track to ultimately gross more than $1 billion. “Iron Man 3” has already grossed $680.1 million in total world-wide. The final total for “Iron Man 2” in 2010 was $624 million.

In an online survey by movie-ticketing website Fandango, 88% of people said “Avengers” influenced their decision to see “Iron Man 3,” compared with 68% who said they were influenced by “Iron Man 2.” The story of “Iron Man 3” picks up where “Avengers” left off and contains multiple references to last year’s movie.

“The continuity of the story lines helps these films deliver momentum to each other,” said Dave Hollis, Disney’s executive vice president in charge of world-wide distribution.

That could boost upcoming Marvel movies such as November’s “Thor: The Dark World” and next April’s “Captain America: The Winter Soldier,” both of which are sequels. “There’s a benefit to each of these films that previously stood in isolation,” Mr. Hollis said.

The growing popularity of the Marvel series has also helped the movies expand beyond the core fanboy audience. While 61% of moviegoers for “Iron Man 3” were men, according to exit polls, 27% were families. That compares with 24% for “Avengers” and is an impressive figure for a movie rated PG-13.

Watch Iron Man 3 Online or Download Iron Man 3 Movie : On average, audiences gave “Iron Man 3” an A grade, according to market research firm CinemaScore, meaning word-of-mouth for the film should be strong. But it will face several formidable competitors in the next few weeks, including “The Great Gatsby,” starring Leonardo DiCaprio, and sequels “Star Trek: Into Darkness,” “Fast and Furious Six” and “The Hangover Part III,” all of which are generating healthy amounts of prerelease interest.

Watch Iron Man 3 Online or Download Iron Man 3 Movie : With a production budget of around $200 million, “Iron Man 3” should be quite profitable for Disney and further validate Chief Executive Robert Iger’s decision to purchase Marvel in 2009 for $4 billion. The brand’s movie and consumer-products businesses have been strong and Marvel brand will jump to television this fall with a television series on Disney’s ABC network based on Marvel’s secret government agency “S.H.I.E.L.D.”